Advanced Technical Pearls for Successful Supermicrosurgical Lymphaticovenular Anastomosis

The Deciding Factors of Flow Direction in Lymphovenous Anastomosis for Extremity Lymphedema

BACKGROUND

While using lymphovenous anastomosis (LVA) to treat extremity lymphedema, an antegrade lymphatic-to-venous flow is usually considered to indicate a functional and effective anastomosis. The authors analyzed the characteristics of lymphovenous anastomoses in patients with extremity lymphedema to look for the deciding factors of the flow direction.

METHODS

A total of 45 patients (15 arms and 42 legs) undergoing LVA for extremity lymphedema were reviewed. Only the anastomoses with intraoperatively confirmed patent flow or clear visualization of vessel lumens during anastomosis were included for analysis. Multivariate logistic regression was used to identify the contributing factors of intraoperative washout phenomenon or venous reflux.

RESULTS

A total of 105 eligible LVAs were included for analysis. Anastomosis with a more sclerotic lymphatic duct is statistically significantly associated with more venous reflux (OR, 2.82; P = 0.003). Larger diameter difference between lymphatic duct and recipient vein (OR, 12.8; P = 0.02) and less sclerotic lymphatic duct (OR, 0.47; P = 0.03) are statistically significantly associated with more washout phenomena.

CONCLUSIONS

The deciding factors of flow direction in LVA are difference of diameters between lymphatic duct and recipient vein, and the severity of lymphosclerosis. To obtain favorable antegrade lymph-to-vein flow, a less sclerotic lymphatic duct with larger diameter and a recipient vein with smaller diameter should be chosen for anastomosis.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Predictors of severity of lymphosclerosis in extremity lymphedema

BACKGROUND

Lymphovenous anastomosis (LVA) is an accepted method for treating lymphedema, and its efficacy could be greatly affected by the severity of lymphosclerosis. In the present study, we analyzed the intraoperative findings of lymphatic ducts in our patients who had undergone LVA to find predictive factors for the severity of lymphosclerosis.

METHODS

The medical records of the patients who had undergone LVA for managing extremity lymphedema from September 2017 to December 2020 were reviewed. The severity of lymphosclerosis was evaluated intraoperatively under a surgical microscope and stratified using the NECST (normal, ectasia, contraction, sclerosis type) classification. Patient age, gender, body mass index (BMI), lymphoscintigraphy stage, and lymphatic duct locations were included for analysis.

RESULTS

Multivariate linear regression analysis showed that location in a lower extremity (regression coefficient, -0.38; P = .03) and more advanced Taiwan lymphoscintigraphy stage (regression coefficient, 0.27; P < .001) were associated with more severe lymphosclerosis. In a subgroup analysis of lower extremity lymphedema, in addition to the Taiwan lymphoscintigraphy stage (regression coefficient, 0.24; P < .001), age (regression coefficient, 0.02; P = .001), and BMI (regression coefficient, 0.04; P = .005) were also associated with the severity of lymphosclerosis.

CONCLUSIONS

The severity of lymphosclerosis in extremity lymphedema correlated positively with the Taiwan lymphoscintigraphy stage and was more severe in lower limb lymphedema. In lower limb lymphedema, a higher BMI and older age also contributed to more severe lymphosclerosis.